Generator "Pulses" while Idling

Discussion in 'Shop Talk' started by FarmerJeff, Nov 24, 2006.

  1. FarmerJeff

    FarmerJeff Well-Known Member

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    Howdy all- I have a 2500w generator with a 6hp B&S engine. The generator is producing power, but it is pulsing or revving while idling.

    Full disclosure- a friend briefly used this 120 generator to run a 220 well-pump. Problem seemed to start after that. Any ideas. Please don't tell me the electronics are shot! :doh:
     
  2. Herb

    Herb Well-Known Member

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    With the info provided, it sounds like the motor is revving too high and the governor is kicking in. Have you actually measured the voltage?
     

  3. agmantoo

    agmantoo agmantoo Supporter

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    I think it is rather common for these small generators to surge when they run unloaded/idle. As long as it settles down with a load I would not be concerned.
     
  4. retire2$

    retire2$ Well-Known Member

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    Possible causes of engine surging are:
    plugged fuel cap vent; dirty air filter; carburetor improperly adjusted; governor sticking, binding, or improper rpm settings; carburetor linkage shafts or shutters sticking or binding; intermittent spark - check ignition.
     
  5. Yeti

    Yeti Well-Known Member

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    if it helps the govenor is set at 3600 rpm on most of the smaller engines. the idea that its surging un loaded is ok, but if its surging while doing a constant draw thats another thing. you could have a jetting issue or it may just need cleaned and adjusted.
     
  6. ace admirer

    ace admirer Well-Known Member Supporter

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    as others have said,,,,hunting is no problem (is annoying though) at unloaded speeds....the cheaper governed engines will do it. i would set loaded rpm with a voltmeter. if the gen over voltages, any appliance with a mov surge surpessor will burn out the mov's...if not the appliance they are there to protect.
     
  7. FarmerJeff

    FarmerJeff Well-Known Member

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    Thanks for the input. Someone else told me that the output diodes could be fried due to trying to run the 220. Basically, I am trying to determine if this is a mechanical problem or an electronic problem. The first few responses didn't seem to think the brief time at 220 was too bad. The engine is not settling down while under load.
     
  8. mohillbilly

    mohillbilly Well-Known Member

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    If it is surging, and not holding a steady speed, it may have an issue with the carb. as in an air leak around the throttle butterfly shaft. I have seen that a few times. Be sure also the needle and float are functioning properly. Could also be an issue with the governor linkage....
     
  9. FreightTrain

    FreightTrain Well-Known Member

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    on my 1000w yamaha i had the same problem,,,, i leaned thecarb a bit and also raised the throttle a hair... \\

    runs perfect again